The dramatic increases in lung cancer incidence and mortality rates among women since the 1960's have been atributed to increased cigarette smoking. Both prospective and retrospective studies of lung cancer in women have shown increased relative risks associated with smoking, as well as dose response relationships by number of cigarettes per day, duration of smoking, or age started smoking. However, studies have shown lower relative risks for smoking among women than among men, even within roughly comparable levels of average cigarette consumption. This proposal is to provide funds for data processing and personnel to conduct analyses of a study of 900 incident female lung cancer cases and 900 general population controls. Fieldwork was conducted under NCI Contract N01-CP-61031. A study of 920 incident male lung cancer cases and 1043 general population controls was also conducted under this contract; these data are presently being analyzed. A major aim of the proposed analyses is to clarify the role of cigarette smoking as a risk factor for lung cancer in women, by examining more refined classification schemes which simultaneously take into account the number of cigarettes smoked, duration of smoking, age when smoking began, inhalation patterns, tar contents, and changes in smoking habits. Other factors which will be considered in estimating overall lung cancer risk and histologic type specific risks include: reproductive and hormonal factors, occupational exposures, interaction of dietary factors (e.g., Vitamin A) with smoking and occupational risk factors, passive smoking, antecedent lung disease, familial history of cancer or lung disease, and residence in urban industrial areas or near point sources of pollution. Analyses will include comparison of relative risks in women with those estimated for the same factors in men.